Aerosol-forming material for a hookah

ABSTRACT

The invention relates to an aerosol-forming material for a water pipe comprising a first substance and at least one second substance that is kept by the first substance and that after activation of the aerosol-forming material is at least partially released, wherein the first substance has pores for receiving the second substance and the second substance is a fluid. Here, it is provided that the first substance comprises a synthetic zeolite.

The invention relates to an aerosol-forming material for a water pipe that comprises a first substance and at least one second substance kept by the first substance and that is at least partially released after activation of the aerosol-forming material, a use of the aerosol-forming material as well as uses of the first substance.

The intended purpose of a water pipe is to consume flavor of an aerosol-forming material in a reservoir. The aerosol-forming material is typically water pipe tobacco and/or a plant-based tobacco substitute as a vehicle for aromatized fluids. Over this, a combustible, in particular coal, is laid, wherein the aerosol-forming material is separated from the combustible by a perforated aluminum foil or a smoke filter. In use a flow is generated that passes hot air from the coal to the aerosol-forming material.

Due to the spatial proximity of the combustible to the aerosol-forming material it is pre-heated and by the supply of hot air to the aerosol-forming material solids are delivered to the hot air, so that now an air flow containing constituents of the aerosol-forming material in the form of an aerosol is passed from the aerosol-forming material into the remaining part of the water pipe.

However, it is problematic that the aerosol-forming material can easily burn what deteriorates the taste of the water pipe. Moreover, the aerosol-forming material is consumed after use and cannot be used again.

From DE 198 54 009 C2 there is known a system for providing an inhalable aerosol having an aerosol-forming material. Said material may be a supporting material that is treated with aroma substances. As inorganic supporting materials aluminum oxide, silica gel, activated carbon, cellulose fibers, lignin granulates, zeolites, aluminas, meerschaum as well as combinations thereof are mentioned.

WO 2009/010176 A2 relates to a tobacco substitute comprising a supporting material and an aroma substance. The supporting material may be a porous bulk material, wherein montmorillonite, dolomite and diatomaceous earth are mentioned as examples for such a porous bulk material.

DE 10 2007 043 776 A1 discloses microcapsules for use in a molded article the shape of which is similar to a water pipe. The microcapsules contain an ingredient that can be associated with a vehicle. The vehicle may be porous types of dolomite, clays such as montmorillonite and silicic acids and silicates such as diatomaceous earth.

DE 20 2010 004 671 U1, that is from the inventor of the present invention, describes a vehicle for aromatized and/or smoke-releasing fluids. The vehicle is an open-pore material that can store and release the fluid when heated again. The rock may be present as granulate that can have a grain size between 0.1 mm and 10 mm in order to allow the vehicle to adapt to the shape of the reservoir of a water pipe. In DE 20 2010 004 671 U1 as the sole example for a vehicle there is mentioned a granulate referred to as clinoptilolite and that is said to have a grain size between 2.5 mm and 5 mm.

However, it has been shown that the uptake capacity of known supporting materials cannot be further increased. Furthermore, the preparation of known aerosol-forming materials is lengthy and complicated. Also, the durability of known aerosol-forming materials is still not sufficient.

A particular problem of the known vehicles is their dust loading. In particular, the preparation of granular vehicles is connected with grinding work leading to the generation of dust. In fact, the devices intended for the separation of the dusts provide for a reduction of the dust loading, however the deposition of dusts in the pores of the vehicle cannot completely be prevented. When activating these vehicles in water pipes together with the fluid also the dust is released from the pores what results in an undesired load of the airflow with particles of the vehicle.

Moreover, adaption to the shape of the reservoir that is desired according to the prior art is insufficient. The known granular vehicles are grit-shaped, i.e. they consist of particles that generally have two opposing flat sides and narrow edges. The result is that in fillings the particles with their flat sides lie on top of each other. On the one hand, this makes it difficult to wet the particles with the fluid. Wetted particles more strongly adhere to each other than non-wetted particles, what not only makes it difficult to adapt the vehicle to the shape of the reservoir, but also impairs the dosage of the aerosol-forming material. Additionally, the particles are sharp-edged such that special precautions must be taken to prevent a damage of packages both during transport and in dosing from a package into the reservoir of a water pipe.

Finally, the known vehicles during transport or dosing tend to break into smaller pieces by which on the one hand further undesired dust is generated and on the other hand surface areas of the vehicles are exposed the pores of which are not filled with fluid. Both change the release behavior of the fluid after activation of the vehicles. Moreover, formation of fragments can also cause that the vehicle can slide through openings in the bottom of the reservoir what impairs the use of the water pipe in total.

The grit shape of the known supporting materials is associated with a further drawback. The supporting materials are difficult to dose. This, in particular applies to amounts of 10 g and less. However, standard amounts of 10 g, for example are desired to ensure a repeated uniform filling of a reservoir. Only if a reservoir can successfully be filled with the same amount of aerosol-forming material the user of a water pipe can achieve the desired enjoyment.

It is the object of the invention to eliminate the drawbacks of the prior art. In particular, an aerosol-forming material is provided that can be used in water pipes and has improved properties, in particular a higher uptake capacity, easier manufacturability, and higher durability. Moreover, uses of the aerosol-forming material are provided.

This problem is solved by the features of claims 1, 9, and 12. Suitable developments of the inventions result from the features of the dependent claims.

In accordance with the invention an aerosol-forming material for a water pipe is provided that comprises a first substance and at least one second substance that is kept by the first substance and that is at least partially released after activation of the aerosol-forming material, wherein the first substance has pores for receiving the second substance and the second substance is a fluid, characterized in that the first substance comprises a synthetic zeolite.

It has surprisingly been found in comprehensive experiments of the inventor that the aerosol-forming material according to the invention has improved properties due to the use of synthetic zeolite as the first substance. These properties in particular are an improved uptake capacity of the first substance for the second substance, a faster uptake of the second substance, a more permanent keeping of the second substance in the first substance before the activation, a lower dust generation and loading as well as a faster release of the second substance from the first substance after activation. In particular, the lower dust generation is advantageous because in the preparation of the aerosol-forming material according to the invention the dust must be removed from the first substance as completely as possible. Also, the faster uptake of the second substance in the pores of the first substance that is due to a higher absorbency of the first substance shortens the time required for the preparation of the aerosol-forming material according to the invention.

The water pipe may be a Shisha.

By a synthetic zeolite in the present invention a zeolite is understood that has been produced artificially. With other words, the synthetic zeolite according to the invention is not recovered by mining. Preferably, the synthetic zeolite is selected from the group consisting of zeolite A, zeolite X, and mixtures thereof

Zeolite A in its hydrated form has the empirical formula M₁₂((AlO₂)₁₂(SiO₂)₁₂)*27 H₂O. M is selected from the group consisting of Na, K and Ca ions. Preferably, M is Na⁺. The term “zeolite A” also includes forms that contain less water or that are free of water. In the known art, zeolite A is also referred to as molecular sieve A, Linde Type A (LTA), MS SA (with M=Ca), MS 4A (with M=Na) and MS 3 A (with M=K).

Zeolite X in its hydrated form has the empirical formula M₈₆((AlO₂)₈₆(SiO₂)₁₀₆)*264 H₂O. M is selected from the group consisting of Na, K and Ca ions. Preferably, M is Na⁺. The term “zeolite X” also includes forms that contain less water or that are free of water.

The uptake capacity of the first substance preferably is at least 40% by weight, more preferably at least 50% by weight, and particularly preferred at least 55% by weight of its own weight. Therefore, in contrast to the prior art in case of full loading of the first substance with the second substance, based on an identical volume unit, a significantly higher amount of the second substance can be provided in the water pipe. For example, a first substance being or containing a zeolite A has an uptake capacity for glycerol of up to 55% by weight. A first substance being or containing a zeolite X for example has an uptake capacity of up to 110% by weight.

Surprisingly, the release of the second substance after activation, i.e. during the normal use of the water pipe, is uniformly in a constant stream. A change of the second substance in view of its structure does not occur during keeping in the first substance. Moreover, the synthetic zeolite is not unhealthy, in particular not cancerogenous. Further, the zeolite is not changed in its structure by the activation so that after release of the second substance it can be loaded with second substances again. For this reason, the first substance can be reused. The first substance offers the further advantage that it is not burnable. Finally, the generation of dust in the preparation and use of the aerosol-forming material according to the invention is lower when using a synthetic zeolite than when using natural zeolites or other minerals.

The term “aerosol-forming material” in the present invention relates to a material that can release the second substance in the form of an aerosol. The first substance itself does not form an aerosol. Before activation the second substance is kept by the first substance. The aerosol-forming material can be obtained by loading the first substance with the second substance. In this case, the first substance acts as a supporting material for the second substance. In loading, the second substance is adsorbed on the surface area of the first substance. Because of the porosity of the synthetic zeolite the surface area of the first substance is relatively high what results in the above described high adsorption ability and thus the high uptake capacity of the first substance. After loading, the second substance is kept by the first substance until activation takes place. The structural properties of the first and second substances neither change in loading and keeping nor in activation.

A water pipe often consists of a closed water jar through the top of which a substantially vertically extending stem is passed the one end of which protrudes into the water in the water jar and the other end of which ends in the head portion outside of the water jar. The head portion has an air inlet. To the side of the through hole of the stem there is typically provided a hose passed through the top of the water jar, but without contacting the water surface in the water jar. Via the distal end of the hose a user can generate an airflow generating a low pressure in the water jar. This low pressure in turn generates an airflow drawing air from the head portion through the stem and the water in the water jar into the water jar. Then, in the head portion the airflow passes through a section, the reservoir, wherein a filler that is an aerosol-forming material is present. In most cases the head portion has an outer surface on which a combustible, such as for example coal is present. The surface is often above the air inlet through which air enters the head portion, so that the airflow does not pass the combustible. The heat formed during burning of the combustible heats the aerosol-forming material to activate it. If coal is used as the combustible this is heated to temperatures of ca. 600 to about 1000° C. The combustible and the aerosol-forming material are spaced apart, for example by separating them through one or more perforated aluminum foils or a smoke filter. That's why the aerosol-forming material is not heated to same extent like the combustible, so that the activation temperature, i.e. the temperature at which the first substance releases the second substance, is lower than the temperature of the burning combustible. The airflow entering the water pipe head (also referred to as Shisha head) through the air inlet now passes the activated aerosol-forming material, wherein it takes up the second substance released in the form of an aerosol and transports it through the stem, the water in the water jar, and the hose to the user of the water pipe.

The aerosol-forming material of the present invention can be used as an aerosol-forming material in such a water pipe.

The activation of the aerosol-forming material according to the invention preferably is by the action of heat. Preferably, the activation takes place at a temperature of from 120 to 350° C., particularly preferred at a temperature of from 150 to 300° C. At these temperatures the first substance is stable, in particular also at 250° C. and cannot burn.

Below the activation temperature the release of the second substance should be as low as possible, in the best case, in particular at room temperature, the first substance should not release any second substance. One advantage of the synthetic zeolite used in accordance with the invention is that below the activation temperature and in particular at room temperature there is no noticeable release of the second substance.

The first substance comprises at least 65% by weight of synthetic zeolite, preferably at least 70% by weight of synthetic zeolite, more preferably at least 80% by weight of synthetic zeolite, still more preferred at least 95% by weight of synthetic zeolite, particularly preferred at least 99% by weight of synthetic zeolite, each based on the first substance. More preferably, the first substance exclusively or almost exclusively consists of synthetic zeolite, i.e. the content of the synthetic zeolite in the first substance should be as high as possible. In this way, the advantageous properties of the aerosol-forming material according to the invention can particularly well be realized. The content missing to 100% by weight consists of additives, for example binders, or synthetic or natural compounds, for example minerals such as quartz.

Preferably, the first substance is a compact body or a granulate. If the first substance is a compact body the dimensions of the body at least in one dimension, preferably in each dimension, should be between 10 mm and 100 mm. The massive body can be put in the reservoir.

More preferably, the first substance is a granulate. The granulate can adapt to the shape of the reservoir. Preferably, the granules in each dimension have an extension of at least 1 mm and at most 10 mm. The grain size of the granulate may be between 1 mm and 10 mm. Preferably, the grain size of the granulate is in the range of 5 to 8 mm, more preferably in the range of 6 to 7 mm. The grain size always relates to the granulate without filling with the second substance. The grain size is equal to the cube root of the multiplication of the three different edge lengths of a cubuid that in its dimension can just enclose the grain:

d=3√{square root over (a*b*c)},

wherein d represents the grain size and a, b, and c represent the edge lengths of the cubuid. Preferably, the granules are at least nearly spherical. Spherical granules are easier to process and optically attractive. In contrast to grit-shaped granules during transport of the granules there is generated less dust independent whether they already have a second substance or not. Moreover, spherical granules are not squashed, but burst if the load is too high.

The diameter of the spherical granules can be between 1 mm and 10 mm. Preferably, the diameter of the spherical granules is in the range of 5 to 8 mm, more preferably in the range of 6 to 7 mm.

A grain size or a diameter in the range of 6 to 7 mm is preferred, because Shisha heads have holes of a size between 3 and 5 mm. If the granules are too small they can slide through the stem into the water jar. Therefore, this grain size or diameter is preferred, as this then does not happen.

It has been found that it is particularly advantageous if the first substance consists of spherical particles or at least 90% by weight, preferably at least 95% by weight, particularly preferred 100% by weight of the particles, the first substance is consisting of, are spherical particles. The weight relates to the first substance.

Spherical particles in particular avoid the drawbacks occurring in the prior art in the preparation, transport, and dosage of the aerosol-forming materials. The spherical particles do not adhere to each other, but roll down from each other. They are therefore easier to dose. The spherical particles break neither in the preparation nor in dosing. In dosing devices as used for filling aerosol-forming materials into packages, for example cans, spherical particles do not get jammed

Since the particles do not have sharp edges the requirements on the strength of packages are lower. So, the spherical particles can be packed in plastic bags, for example sachets. Also small amounts (e.g. 10 g) can reliably be filled, since, because of the reliable rolling processes there is a higher repeat accuracy. On the other hand, grit-shaped particles have a lower repeat accuracy and due to sharp edges may puncture or unsightly deform foils.

The diameter of the spherical particles is preferably between 1 mm and 10 mm, more preferably in the range of 5 to 8 mm and particularly preferred in the range of 6 to 7 mm to facilitate the dosing of the aerosol-forming materials. In this way, also packing in small amounts, for example 10 g each, is facilitated.

The spherical particles must not necessarily be ideal geometric spheres, it is rather sufficient if the spherical particles are nearly spherical, for example ellipsoid. The granules described above are spherical particles in the meaning of the present invention.

The first substance is an open-pore material. The pores of the first substance may take up and store the second substance to obtain the aerosol-forming material according to the invention. In the activation, for example heating of the aerosol-forming material by a combustible, the second substance is released from the pores of the first substance again. Thus, the first substance is suitable as a vehicle for the second substance, i.e. in particular for aerosol-releasing fluids. After using the aerosol-forming material in a water pipe the first substance can be reused and further act as a vehicle for a second substance.

The pore size of the pores of the first substance is preferably in the range of 1 to 10 angstrom, more preferably in the range of 3 to 10 angstrom, and particularly preferred is 3, 4, 5, or 10 angstrom. The pore size can be determined by known methods, for example by gas adsorption methods.

A preferred first substance is zeolite X having a grain size of 6 to 7 mm and a pore size of 10 angstrom.

The second substance is a fluid, preferably an aerosol-releasing fluid. The second substance can comprise several aerosol-releasing fluids. At least one of the fluids may be a haze fluid. The second substance that is released after the activation of the aerosol-forming material forms an aerosol. Here, by an aerosol a colloidal system of a gas and solid or liquid particles of the second substance distributed therein is understood. The diameter of the particles of the second substance in the gas should be between 10⁻⁷ to 10⁻³ cm. If the particles of the second substance distributed in the gas are liquid, then the second substance may be a haze-releasing fluid, for example an aromatized fluid. However, the particles of the second substance distributed in the gas may also be solid. Moreover, the particles of the second substance distributed in the gas may be mixtures of solid and liquid particles. Preferably, the gas is air, for example the air of the airflow generated in the water pipe.

The second substance is preferably selected from the group comprising polyols, flavors, active ingredients, water, and mixtures thereof Prerequisite is that in the activation of the aerosol-forming material according to the invention the second substance forms an aerosol. Exemplary polyols are glycerol, propylene glycol, and mixtures thereof Preferred is glycerol. Exemplary flavors are extracts from fruits, herbals, fruit products, vegetable products as well as mixtures thereof The flavors are preferably present as esters, ethers, oils, monohydric alcohols, and mixtures thereof. Preferred flavors are apple flavors, banana flavors, blueberry flavors, caipirinha flavors, cappuccino flavors, chocolate flavors, cherry flavors, coconut flavors, pitaya flavors, grape flavors, guava flavors, sugar melon flavors, water melon flavors, lemon flavors, lime flavors, mango flavors, mint flavors, orange flavors, passion fruit flavors, peach flavors, raspberry flavors, rose flavors, strawberry flavors, mandarin flavors, woodruff flavors, menthol flavors, whisky flavors, fig flavors, tobacco flavors, and mixtures thereof Exemplary active ingredients are psychoactive substances such as caffeine, nicotine, and mixtures thereof The flavors may contain a content of water that should at most be 1% by weight, preferably at most 0.5% by weight, based on the respective flavor. The weight portion of the second substance given for the flavor comprises this water portion.

In a preferred embodiment the second substance is a mixture of substances. A preferred mixture of substances is a mixture consisting of at least one polyol and at least one flavor. The portion of the polyol based on the second substance should at least be 90% by weight, preferably at least 95% by weight, each based on the second substance. A preferred mixture of substances consists of 95% by weight of glycerol and 5% by weight of flavor, each based on the second substance. The polyol can contain a portion of water that should be at most 1% by weight, preferably at most 0.5% by weight, each based on the polyol. The weight portion of the second substance given for the polyol comprises the water portion.

In one embodiment the aerosol-forming material according to the invention is the synthetic zeolite as granulate having a grain size between 2.5 mm and 5 mm without a filling of aerosol-releasing fluids in the pores as a vehicle for aerosol-releasing fluids for use in water pipes.

The aerosol-forming material according to the invention may be formulated, i.e. the first substance is filled with the second substance. Alternatively, the aerosol-forming material according to the invention can be offered as a kit providing the first substance separated from the second substance.

In accordance with the invention further provided is the use of a synthetic zeolite as a supporting material of an aerosol-forming material for a water pipe.

In one embodiment the synthetic zeolite is used as a granulate having a grain size between 1 mm and 10 mm without a filling of aerosol-releasing fluids in the pores as a vehicle for aerosol-releasing fluids for use in water pipes.

In accordance with the invention further provided is the use of the aerosol-forming material according to the invention as filling material for a water pipe.

In the following, the invention is explained in more detail with the help of examples not intended to limit the invention.

EXAMPLES Example 1 (a) First Substance

The first substance used comprised a zeolite A with the empirical formula Na₁₂((AlO₂)₁₂(SiO₂)₁₂)*27 H₂O, Manufacturer: Shanghai Witiger Molecular sieve Co., Ltd, CN, Trade Name: molecular sieve 4A. This substance had the following properties:

-   -   Shape: granulate having substantially spherical particles     -   Grain size: 4 to 8 mm     -   Pore size: 4 angstrom     -   Bulk Density: 0.80 g/cm³     -   Abrasion Rate: <0.25%     -   Compressive Strength: 100 N/sphere     -   H2O capacity: 55% of the zeolite weight     -   Loss in ignition at 575° C.: <1.5%

The portion of the zeolite A in the first substance was at least 70% by weight, the residue was a binder.

The first substance forms the vehicle for the second substance, i.e. the aerosol-releasing fluids in the aerosol-forming material.

(b) Second Substance

The second substance used had the following composition, based on the second substance, with the provision that the sum of the constituents yields 100% by weight:

Glycerol¹: 95% by weight

-   -   Flavor: 5% by weight %

-   ¹ Glycerol 99.5%

The flavor was apple flavor.

In the aerosol-forming material the second substance forms the aerosol-releasing fluids that are taken up by and stored in the first substance. By heating the aerosol-forming material the fluids are released again.

(c) Aerosol-Forming Material

By using the first and the second substance an aerosol-forming material according to the invention was prepared. For that, the first substance was loaded with the second substance by mixing both substances. The aerosol-forming material consisted of 65% by weight of the first substance and 35% by weight of the second substance.

Upon heating the thus obtained aerosol-forming material to 200° C. in a water pipe the second substance was uniformly released to form an aerosol.

Example 2

An aerosol-forming material with the following composition was prepared:

(a) First Substance

The first substance comprised a zeolite X with the empirical formula M₈₆((AlO₂)₈₆(SiO₂)₁₀₆)*264 H₂O, Manufacturer: UOP CH Sàrl, CH, Trade Name: Molsiv Adsorbents 13X APG 4×8. This substance had the following properties:

-   -   Shape: granulate having substantially spherical particles     -   Grain size: 4 to 5 mm     -   Pore size: 10 angstrom     -   Bulk Density: 0.70 g/cm³     -   Abrasion Rate: <0.25%     -   Compressive Strength: 70 N/sphere     -   H₂O capacity: 90% of the zeolite weight     -   Loss in ignition at 575° C.: <1.5%

The portion of the zeolite in the first substance was at least 70% by weight, the residue was a binder.

The first substance forms the vehicle for the second substance, i.e. the aerosol-releasing fluids in the aerosol-forming material.

(b) Second Substance

The second substance of example 2 corresponds to the second substance of example 1.

(c) Aerosol-Forming Material

By using the first and the second substance an aerosol-forming material according to the invention was prepared. For that, the first substance was loaded with the second substance by mixing both substances. The aerosol-forming material consisted of 47.5% by weight of the first substance and 52.5% by weight of the second substance.

Upon heating the thus obtained aerosol-forming material to 200° C. in a water pipe the second substance was uniformly released to form an aerosol.

Example 2A

Example 2A corresponds to example 2, except that the first substance was a zeolite X with the empirical formula Na₈₆((AlO₂)₈₆(SiO₂)₁₀₆)*264 H₂O, Manufacturer: Shanghai Witiger Molecular sieve Co., Ltd, CN, Trade Name: Zeolite 13X, with a grain size of 6 to 7 mm and a compressive strength of 140 N/sphere.

Example 3 (a) First Substance

The first substance used comprised a zeolite A with the empirical formula Na₁₂((AlO₂)₁₂(SiO₂)₁₂)*27 H₂O, Manufacturer: Zeochem AG, Uetikon, CH, Trade Name: ZEOCHEM molecular sieve 4A. This substance had the following properties:

-   -   Shape: granulate having substantially spherical particles     -   Grain size: 2.5 to 5 mm     -   Pore size: 4 angstrom     -   Bulk Density: 0.80 g/cm³     -   Abrasion Rate: <0.25%     -   Compressive Strength: 40 N/sphere

H₂O capacity: 50% of the zeolite weight

-   -   Loss in ignition at 575° C.: <1.5%

The first substance consisted of 75 to 90% by weight of zeolite A, 1.0 to 2.5% by weight of quartz, and a binder as the residue.

The first substance forms the vehicle for the second substance, i.e. the aerosol-releasing fluids in the aerosol-forming material.

(b) Second Substance

The second substance of example 3 used corresponds to the second substance of example 1.

(c) Aerosol-Forming Material

By using the first and the second substance an aerosol-forming material according to the invention was prepared. For that, the first substance was loaded with the second substance by mixing both substances. The aerosol-forming material consisted of 65% by weight of the first substance and 35% by weight of the second substance.

Upon heating the thus obtained aerosol-forming material to 200° C. in a water pipe the second substance was uniformly released to form an aerosol. 

1. An aerosol-forming material for a water pipe comprising a first substance and at least one second substance that is kept by the first substance and that after activation of the aerosol-forming material is at least partially released, wherein the first substance has pores for receiving the second substance and the second substance is a fluid, and the first substance comprises asynthetic zeolite.
 2. The aerosol-forming material according to claim 1, wherein the first substance is selected from the group consisting of zeolite A, zeolite X, and mixtures thereof
 3. The aerosol-forming material according to claim 1, wherein the first substance is a granulate.
 4. The aerosol-forming material according to claim 1, wherein the grain size of the first substance is between 1 and 10 mm.
 5. The aerosol-forming material according to claim 1, wherein the first substance consists of particles, wherein at least 90% by weight of the particles are spherical particles.
 6. The aerosol-forming material according to claim 5, wherein the spherical particles have a diameter between 1 and 10 mm.
 7. The aerosol-forming material according to claim 1, wherein the pores of the first substance have a pore size in the range of 1 to 10 angstrom.
 8. The aerosol-forming material according to claim 1, wherein the fluid is selected from the group consisting of polyols, flavors, active ingredients, water, and mixtures thereof 9-12. (canceled) 